Release sheet

Abstract

A composite sheet of a flexible release liner, which is useful in high speed operations is described. The release liner is coated on one side with a crosslinkable high release coating formulation comprising (a) a silicone-acrylate release component; (b) an acrylate-containing crosslinking agent, such as a silicone-acrylate crosslinking agent having a higher acrylate content than the (a) silicone-acrylate, trimethylolpropane triacrylate or epoxylated trimethylolpropane triacrylate; and (c) an acrylic ester monomer or oligomer selected from the group consisting of octyl acrylate, isodecyl acrylate, stearyl acrylate and lauryl acrylate, specifically the (c) acrylate is free of silicone and more than two acrylate groups per molecule.

What is claimed is: 
     
       1. A flexible sheet comprising a film form liner having on one side thereof a crosslinkable release coating comprising a mixture of (a) from about 15 to about 70% of a silicone-acrylate composition based on the weight of the coating mixture; (b) an acrylate-containing crosslinking agent; and (c) an acrylic ester monomer or oligomer. 
     
     
       2. The flexible sheet of claim 1 in which the (a) silicone-acrylate composition comprises about 5 to about 30% acrylate. 
     
     
       3. The flexible sheet of claim 1 in which the (b) crosslinking agent is a silicone-acrylate having an acrylate content which is from about 5 to about 15% greater than the acrylate content of the (a) silicone-acrylate composition. 
     
     
       4. The flexible sheet of claim 3 in which the (b) silicone-acrylate has an acrylate content ranging from about 10% to about 45%. 
     
     
       5. The flexible sheet of claim 1 in which the (b) crosslinking agent is selected from the group consisting of multi-functionalized acrylate monomers and oligomer. 
     
     
       6. The flexible sheet of claim 1 in which the (b) crosslinking agent is selected from the group consisting of trimethylolpropane triacrylate and ethoxylated trimethylolpropane triacrylate. 
     
     
       7. The flexible sheet of claim 4 which further comprises as the (b) crosslinking agent a crosslinking agent selected from the group consisting of trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate and mixtures thereof. 
     
     
       8. The flexible sheet of claim 1 in which the (c) acrylic ester is an alkyl acrylate monomer or oligomer in which the alkyl group contains from about 2 to about 24 carbon atoms. 
     
     
       9. The flexible sheet of claim 8 in which the (c) acrylic ester is selected from the group consisting of octyl acrylate, isodecyl acrylate, stearyl acrylate and lauryl acrylate. 
     
     
       10. The flexible sheet of claim 1 in which the amount of (b) ranges from about 10 to about 50% and the amount of (c) ranges from about 10% to about 50% based on the entire weight of the mixture. 
     
     
       11. The flexible sheet of claim 1 in which the film form liner is at least one member selected from the group consisting of paper, oriented polypropylene, polyethylene, polyethylene terephthalate, polyamide and polystyrene. 
     
     
       12. The flexible sheet of claim 1 in which the crosslinkable release coating is radiation cured. 
     
     
       13. The flexible sheet of claim 1 in which the sheet further comprises a tacky adhesive coating adhered to an outer surface of the release coating, the outer surface being located opposite to a surface of the release coating which is adjacent to the liner. 
     
     
       14. The flexible sheet of claim 13 in which the sheet further comprises a face film stock secured to an outer surface of said adhesive coating, the outer surface being located opposite to a surface of the adhesive coating which is adjacent to the release coating. 
     
     
       15. A flexible sheet comprising a film form liner having on one side thereof a crosslinkable release coating comprising a mixture of (a) about 15 to about 70% of a silicone-acrylate release composition based upon the weight of the coating mixture; (b) an acrylate-containing crosslinking agent selected from the group consisting of one or more of a silicone-acrylate crosslinking agent having an acrylate content which is from about 5 to about 15% greater than the content of the (a) silicone-acrylate release composition, trimethylolpropane triacrylate or epoxylated trimethylolpropane triacrylate; and (c) an acrylic ester monomer or oligomer selected from the group consisting of octyl acrylate, isodecyl acrylate, stearyl acrylate and lauryl acrylate. 
     
     
       16. The flexible sheet of claim 15 in which the amount of (a) ranges from about 15 to about 70%; the amount of (b) ranges from about 10 to about 50% and the amount of (c) ranges from about 10% to about 50% based on the entire weight of the mixture. 
     
     
       17. The flexible sheet of claim 15 in which the film form liner is at least one member selected from the group consisting of paper, oriented polypropylene, polyethylene, polyethylene terephthalate, polyamide and polystyrene. 
     
     
       18. The flexible sheet of claim 15 in which the crosslinkable release coating is radiation cured. 
     
     
       19. The flexible sheet of claim 18 in which the sheet further comprises a tacky adhesive coating adhered to an outer surface of the release coating, the outer surface being located opposite to a surface of the release coating which is adjacent to the liner. 
     
     
       20. The flexible sheet of claim 19 in which the sheet further comprises a face film stock secured to an outer surface of said adhesive, the outer surface being located opposite to a surface of the adhesive coating which is adjacent to the release coating. 
     
     
       21. The flexible sheet of claim 15 in which the (c) acrylate is free of silicone.